Wavefront shaping in random media is a high visibility topic with both fundamental implications and many exciting applications such as focusing and imaging through turbid media, looking behind corners and through fog, and using multimode fibers as miniature endoscopes. Another important field encompasses the dynamics of propagating modes in multimode fibers, involve intriguing physics and opportunities for application. In particular, nonlinearities in multimode fibers remains a largely unexplored field with opportunities to exploit the multimode degrees of freedom for controlling spatial-spectral-temporal interactions.